Hypoxemia following hospital discharge after fast-track hip and knee arthroplasty - A prospective observational study subanalysis.

BACKGROUND: Post-operative hypoxemia is prevalent in hospitalized patients and may adversely affect recovery. However, little data exist on the post-discharge phase or details on duration, severity and potential risk factors. Thus, we investigated the incidence and risk factors for severe desaturation during the first post-operative week after THA/TKA by continuous nocturnal oxygen saturation monitoring. METHODS: The study was a secondary analysis of a prospective cohort study of 112 patients undergoing fast-track THA/TKA. Patients with known sleep apnoea were excluded. Oxygen saturation and heart rate were recorded by a wireless wrist-worn pulse oximeter 2 nights before and 7 nights after surgery. Data on demographics, opioid consumption and cognitive function were collected from medical charts, patient diaries and clinical testing respectively. The primary outcome was occurrence of severe desaturation defined as periods with saturation <85% lasting ≥10 minutes. Secondary outcomes included description of various saturation levels and relevant risk factors. RESULTS: Severe oxygen desaturation occurred in 35% of the patients during the first post-operative week. Duration and severity of hypoxemic episodes increased after the first post-operative day. Pre-operative episodes of hypoxemia significantly increased the risk of post-operative hypoxemic events (OR 2.4-4.4, CI 0.4-46), while pre- and post-operative opioid use, age, gender, ASA classification, type of surgery or anaesthesia were significantly related to the development of post-operative hypoxemia. CONCLUSIONS: One third of the patients suffered from increased and prolonged episodes of severe nocturnal hypoxemia during the first week after THA/TKA discharge. Increased risk for severe hypoxemic episodes was related to pre-operative hypoxemia.

Continuous vital sign monitoring after major abdominal surgery-Quantification of micro events.

INTRODUCTION: Millions of patients undergo major abdominal surgery worldwide each year, and the post-operative phase carries a high risk of respiratory and circulatory complications. Standard ward observation of patients includes vital sign registration at regular intervals. Patients may deteriorate between measurements, and this may be detected by continuous monitoring. The aim of this study was to compare the number of micro events detected by continuous monitoring to those documented by the widely used standardized Early Warning Score (EWS). METHODS: Fifty patients were continuously monitored with peripheral arterial oxygen saturation (SpO2 ), heart rate (HR), and respiratory rate (RR) the first 4 days after major abdominal cancer surgery. EWS was monitored as routine practice. Number and duration of events were analyzed using Fisher's exact test and Wilcoxon rank sum test. RESULTS: Continuous monitoring detected a SpO2 <92% in 98% of patients vs 16% of patients detected by EWS (P < .0001). Micro events of SpO2 <92% lasting longer than 60 minutes were found in 58% of patients by continuous monitoring vs 16% by the EWS (P < .0001). Fifty-two percent of patients had micro events of SpO2 <85% lasting longer than 10 minutes. Continuous monitoring found tachycardia in 60% of patients vs 6% by the EWS. Frequency of events for bradycardia, tachypnea, and bradypnea showed similar patterns. CONCLUSION: Very low SpO2 and tachycardia in post-operative patients are common and under-diagnosed by the EWS. Continuous monitoring can discover these micro events and potentially contribute to earlier detection and, potentially, result in prevention of clinical complications.

Technological aided assessment of the acutely ill patient - The case of postoperative complications.

Surgical interventions come with complications and highly reported mortality after major surgery. The mortality may be a result of delayed detection of severe complications due to lower monitoring frequency in the general wards. Several studies have shown that continuous monitoring is superior to the manually intermittent recorded monitoring in terms of detecting abnormal physiological signs. Hopefully improved observations may result in earlier detection and clinical intervention. This narrative review will describe current monitoring possibilities for postoperative patients and how it may prevent complications. Several wireless systems are being developed for monitoring vital parameters, but many of these are not yet validated for critically ill patients. The ultimate goal with patient monitoring and detect of events is to prevent postoperative complications, death and costs in the health care system. A few studies indicate that monitoring systems detect deteriorating patients earlier than the nurses, and this was associated with less clinical instability. An important caveat of future devices is to assess their effect in relevant patient populations and not only in healthy test-subjects. Implementation of novel technologies is expensive although expected to be cost-effective if just few adverse events can be prevented. The future is here with promising devices and the possibility to give an unprecedented precise risk estimation of adverse post-surgical events. Next step is to integrate existing evidence based treatment algorithms to demonstrate the clinical efficacy of implementing the new technology.